Technical Field
The present invention relates to a photoelectric encoder that uses a telecentric lens.
Related Art
WO 2005/090923 A discloses a photoelectric encoder including a double telecentric optical system in which a first lens is inserted between a main scale and a light receiving element along with a second lens and an aperture disposed at a focal position of the first lens. In the photoelectric encoder, signal detection efficiency is improved and the number of adjustment steps can be decreased due to loosed assembly tolerances.